The US Air Force has gone through many aeromedical patient isolation transport system designs. The first designs were developed in response to the Ebola outbreak in 2014 and, more recently, the COVID-19 pandemic. The trade study analysis part of the system engineering design method was used to analyze the historic and current aeromedical patient contamination control transport systems. A trade study is a process that evaluates alternatives based upon various “-ilities”, such as reconfigurability, flexibility, durability, cost, and more, and performs a systematic analysis to aid designers in producing a ‘good’ design alternative given the large set of possible solutions. The analysis of these historic and current systems, in addition to speaking with stakeholders, resulted in design requirements for a new system. This article will discuss the findings from the analysis of the historic and current aeromedical patient isolation transport systems

Miller, Michael E.

Shaghaghi, Sara

Slagley, Jeremy M.

Varshney, Gaiven

English

AFTI Scholar (Air Force Institute of Technology)

Air Force Institute of Technology AFIT Scholar Faculty Publications Spring 2023 Utilizing the System Engineering Trade Study Analysis Method to Analyze Patient Aeromedical Evacuation Sara Shaghaghi Air Force Institute of Technology Jeremy M. Slagley Air Force Institute of Technology Michael E. Miller Air Force Institute of Technology Gaiven Varshney Air Force Institute of Technology Follow this and additional works at: https://scholar.afit.edu/facpub  Part of the Aerospace Medicine Commons, Aviation Safety and Security Commons, Critical Care Commons, Emergency Medicine Commons, Equipment and Supplies Commons, Infectious Disease Commons, Management and Operations Commons, Other Aerospace Engineering Commons, Risk Analysis Commons, Systems Engineering and Multidisciplinary Design Optimization Commons, Systems Science Commons, Transportation Engineering Commons, Trauma Commons, and the Virus Diseases Commons Recommended Citation Shaghaghi, S., Slagley, J., Miller, M., & Varshney, G. (2023,Spring). Utilizing the System Engineering Trade Study Analysis Method to Analyze Patient Aeromedical Evacuation. Countering WMD Journal,(26),17–23. This Article is brought to you for free and open access by AFIT Scholar. It has been accepted for inclusion in Faculty Publications by an authorized administrator of AFIT Scholar. For more information, please contact AFIT.ENWL.Repository@us.af.mil. |    Shaghaghi et al. - Utilizing the System Engineering Trade Analysis Method17Utilizing the System Engineering Trade Study Analysis Method to Analyze Patient Aeromedical EvacuationBy: Sara Shaghaghi, Dr. Jeremy Slagley,Dr. Michael Miller, and Dr. Gaiven VarshneyIntroductionThe US Air Force has gone through many aeromedical patient isolation transport system designs. The first designs were developed in response to the Ebola outbreak in 2014 and, more recently, the COVID-19 pandemic [1, 2]. The trade study analysis part of the system engineering design method was used to analyze the historic and current aeromedical patient contamination control transport systems. A trade study is a process that evaluates alternatives based upon various “-ilities”, such as reconfigurability, flexibility, durability, cost, and more, and performs a systematic analysis to aid designers in producing a ‘good’ design alternative given the large set of possible solutions.The analysis of these historic and current systems, in addition to speaking with stakeholders, resulted in design requirements for a new system. This article will discuss the findings from the analysis of the historic and current aeromedical patient isolation transport systems. The legacy systems that were analyzed during this investigation were the Patient Isolation Unit (PIU), Transport Isolation System (TIS), and the Portable Bio-Containment Module (PBCM), also referred to as the Portable Bio-Chemical Module and the Portable Biocontainment Care Module [3, 4, 5]. The PBCM was previously known as the Containerized Biocontainment System (CBCS) [6]. Each system had its respective benefits and drawbacks. The PIU  was lightweight, allowed single patient transport, and ensured staff protection. However, the unit was costly, communication between the patient and staff was difficult, emergency medical treatment was limited, temperature and fluid regulation presented an issue, and a psychological barrier was discovered during training simulations [7]. The specific PIU initially purchased by the Air Force is unknown, at the time of this publication. However, a similar one CAPSULS™, Patient Isolation Unit produced by ISOVAC Products LLC, is available for $9K for government contracts [8, 9]. The PIU produced by ISOVAC Products fits a standard North Atlantic Treaty Organization (NATO) size litter and compacts down to fit inside a bag that measures  24” x 20” x 18” and weighs about 30 lbs [8].The PIU was never operationally used by the Air Force in patient transport. The TIS, shown in Figure 1, Figure 2, and Figure 3, was developed to ensure better aircraft integration (C-17 Globemaster III and C-130 Hercules) and increased the number of patients transported from single patient transport to two litter mounted patients. Figure 1 demonstrates how litter-mounted patients are loaded into the unit.  The TIS is describe as a minivan, such that two fully configured units can fit within the C-17, as shown in Figure 2 [10]. However, the TIS was not applicable for aerosol-transmissible biologicals and large-scale patient transport  [1, 4]. Additionally the plastic which encased the unit caused communication issues. Figure 2 and Figure 3 show the TIS with and without the plastic encasing, respectively.  These communication issues, in conjunction with the temperature regulation issues and the fact that the medical staff felt that the unit was unstable, increased the risk of adverse effects on the medical staff [11, 12]. The TIS had a 20-week production lead time when built from scratch when initially presented to the Air Force, with approximately two units that could be produced per week [13]. Estimated costs for the production of the TIS was said to be approximately $100K. The initial requirement included was to have twenty-five units for a total cost of $2.5 million [13].  Countering WMD Journal - 26th Edition    |18Figure 1: Airmen Inside Transport Isolation System [14]Figure 2: Transport Isolation System inside of a C-17 [15]|    Shaghaghi et al. - Utilizing the System Engineering Trade Analysis Method19The Portable Bio-Containment Module (PBCM), shown in Figure 4 and Figure 5, was developed for the Ebola outbreak and was a viable alternative for patient aeromedical transport during the COVID-19 pandemic. Like the TIS, the PBCM was integrated with the C-17 and C-130 and increased the number of transportable patients to four but the PBCM had a high cost and a 6-month production timeline. However, the PBCM was reported to have both temperature and communication issues, in addition to having limited interior space [16]. The PBCM, formerly named CBCS, has a footprint of 8 feet wide by 44 feet long and reaches a height of 8 feet. The unit weighs 24,000 pounds [17].Figure 3: Transport Isolation System Unit without External Plastic Covering [4]Figure 5: Portable Bio-Containment Module (PBCM) on a C-17 Globemaster III [4, 5]Figure 4: Portable Bio-Containment Module (PBCM) is shown being tested for Aerosol Integrity on a C-17 [18]Countering WMD Journal - 26th Edition    |20In response to COVID-19, the US Air Force developed the Negatively Pressurized Conex (NPC) and NPC Lite (NPCL) units shown in Figure 6-9. The NPC and NPCL are similarly designed units, the only difference being the physical characteristics of each unit and the total number of patients that can be transported. The NPC is a 40-foot-long Conex (7 feet 11 inches in width and 8 feet 6 inches in height), in contrast to its NPCL counterpart,  is a 30-foot-long Conex (9 feet in width and 8 feet in height) [1]. The NPC and NPCL weigh 19,500 pounds and 13,000 pounds at delivery, respectively [1]. The NPC and NPCL further increased the total patient capacity to eight and two litter mounted patients, respectively, and added a separate anteroom, allowing staff rotation. Figure 6 shows the inside of the unit during the initial testing while a graphical depiction of the unit is seen in Figure 8  including the antechamber and patient area. The disadvantages for NPC and NPCL were their expense, communication issues, temperature regulation, storage issues, aircraft integration, and the ability to respond to in-flight aircraft emergencies. In-flight emergencies include the effects from sudden maneuvers causing the unit to shift, personnel loss of balance or breaking the glass windows of the unit. Aircraft integration issues included the size, as well as access to onboard electrical power and oxygen supply [12, 1]. The NPC and NPCL cost approximately two million U.S. Dollars to prototype and test. The current cost per unit has not been released.The production time has not been released. However, the total time it took the NPC and NPCL to be operational was 95 days [1].  Figure 8: A graphic demonstrating the layout and main patient area of the NPC [21]Figure 6: Negatively Pressurized Conex (NPC) being used for Training at Ramstein Air Base, Germany [19]Figure 7: Negatively Pressurized Conex Lite (NPCL) Set-Up for Training at Ramstein Air Base, Germany [20]|    Shaghaghi et al. - Utilizing the System Engineering Trade Analysis Method21Based on the review of these historical and current systems, many recurring design deficiencies exist. For example, every unit has temperature regulation and commu-nication issues, as seen in Table 1.  These two factors are essential for patients and staff, as communication and temperature are vital to ensuring safety during transport. Table 1 depicts the ability of each system to achieve the design requirements. Comparing the legacy systems from a cost and produc-tion perspective (Table 2), there are different drawbacks and advantages to the systems. The litter-mounted systems, such as the PIU, are commercially available off the shelf and can be purchased for one-time use. The TIS, which transports two litter-mounted patients, can be produced for less than the NPC with a longer production time. In constrast, the NPC and NPCL can be manufactured at a more efficient rate but at a higher cost. However, they can increase the number of patients per transport.Using the system engineering design process and a trade study analysis, the drawbacks from legacy and current systems can be found and potentially resolved through future design to prevent recurrence. This method, in conjunction with speaking to various stakeholders, allows engineers to step back from the design process and critically analyze the strengths and weaknesses of legacy systems, to ensure the final product fits the customer’s needs.  Utilization of the system engineering trade study analysis and design method may allow better product development to charter to our aero-medical transport requirements.The derived requirements from this trade study analysis will be used for the design of a new patient transport system. Analyzing the drawbacks of others and encompassing them into the design decisions. The new system will be analyzed according to the derived requirements in Table 1 and decon-tamination efficiency. ■Figure 9: Negatively Pressurized Conex (NPC) (Left) and NPC Lite (NPCL) (Right) with Members of the Test Team [22]Table 1: Derived Design Requirements for Patient Transport System and Legacy Systems Capability to Meet the RequirementsCountering WMD Journal - 26th Edition    |22Notes[1] Air Mobility Command, “Negatively Pressurized Conex (NPC) and NPC Lite (NPCL),” [Online]. Available: https://www.amc.af.mil/About-Us/Fact-Sheets/Display/Article/2531813/negatively-pressurized-conex-npc-and-npc-lite-npcl/.[2] J. Garamone, “Transcom Develops System to Transport Ebola Patients,” U.S. Department of Defense, 4 December 2014. [Online]. Available: https://www.defense.gov/News/News-Stories/Article/Article/603751/transcom-develops-system-to-transport-ebola-patients/. [Accessed 22 March 2023].[3] Global Biodefense Staff, “Air Force COVID-19 Medical Transport: Portable Biocontainment Care Module,” Global Biodefense, 4 June 2020. [Online]. Available: https://globalbiodefense.com/2020/06/04/air-force-covid-19-medical-transport-portable-biocontain-ment-care-module/. [Accessed 22 March 2023].[4] K. C. Gandara, “Operational testers unite in solution to transport COVID-19 patients,” Wright-Patterson AFB, WPAFB, 2020.[5] S. S. C. Drzazgowski, “PBCM Test and Evaluation [Image 1 of 13],” Defense Visual Information Distribution Service, 15 April 2020. [Online]. Available: https://www.dvidshub.net/image/6180330/pbcm-test-and-evaluation. [Accessed 22 March 2023].[6] MRI Global, “Containerized Biocontainment System (CBCS) – Flyable Biocontainment System,” MRI Global, [Online]. Available: https://www.mriglobal.org/first-of-its-kind-flyable-medical-transport-unit-cbcs/. [Accessed 22 March 2023].[7] L. Dedecker, Interviewee, Patient Transport System Meeting. [Interview]. 17 March 2022.[8] ISOVAC Products LLC, “CAPSULS Patient Isolation Unit,” ISOVAC Products LLC, 2022. [Online]. Available: https://www.isovacprod-ucts.com/products/capsuls-patient-isolation-unit/. [Accessed 7 April 2022].[9] Email Correspondence with ISOVAC Products, 2023. [10] T. Gallaway, “Transportation Isolation Systems: Changing the way we do business,” Joint Base Charleston, 5 February 2015. [Online]. Available: https://www.jbcharleston.jb.mil/News/Article-Display/Article/859737/transportation-isolation-systems-chang-ing-the-way-we-do-business/#:~:text=The%20TIS%20can%20be%20configured,the%20size%20of%20a%20minivan.. [Accessed 12 April 2022].[11] S. Wade, “Scott Airmen train on Transport Isolation System,” Defense Visual Information Distribution Service (DVIDS), 27 January 2015. [Online]. Available: https://www.dvidshub.net/news/152842/scott-airmen-train-transport-isolation-system. [Accessed 13 April 2022].[12] 455 Expeditionary Aeromedical Evacuation Squadron, Interviewee, Patient Transport System Meeting. [Interview]. 2 April 2022.[13] O. C. Gadeken, “Rapid development of the United States military’s transport isolation system: the “ebola carrier” (a project manage-ment case study),” PMI Global Congress - North America, 2015. [14] A. 1. C. T. Queen, Artist, Negative for COVID. [Art]. Airman Magazine, 2014. [15] S. A. C. Miller, Artist, Negative for COVID. [Art]. Airman Magazine, 2019. [16] B. Feeney, “CCDC Chemical Biological Center Helps Air Force Design, Test and Field Large-Scale COVID-19 Transport Capability in Record Time,” United States Army, 2020.[17] MRI Global, “Containerized Bio-Containment System (CBCS),” MRI Global, [Online]. Available: https://www.mriglobal.org/cbcs/. [Accessed 22 March 2023].[18] S. S. C. Drzazgowski, Artist, Negative for COVID. [Art]. Airman Magazine, 2020. *The cost of the NPC and NPCL reflects the cost of testing and prototyping time for the system overall. It does not represent the cost of each individual unit. **The information available TIS’s production time represents the production time at the onset of the Ebola outbreak in 2015.Table 2: Cost and Production Time for Legacy and Current Patient Transport Systems|    Shaghaghi et al. - Utilizing the System Engineering Trade Analysis Method23Sara Shaghaghi is the Teaching Assistant for the Countering Weapons of Mass Destruction Program at the Air Force Institute of Technology, on Wright-Patterson AFB, OH. She has a B.E. in Chemical Engineering from the University of Dayton and a M.S. in Bioengineering from the University of Dayton. Her email address is sara.shaghaghi@us.af.mil. Dr. Jeremy Slagley is an Associate Professor and Program Director of the Countering Weapons of Mass Destruction Graduate Certificate at the Air Force Institute of Technology, on Wright-Patterson AFB, OH.  He holds a B.S. in Environmental Engineering from West Point, a M.S. in Industrial Hygiene from the University of Iowa, and a Ph.D. in Occupational Safety and Health from West Virginia University.  He is a retired Air Force Bioenvironmental Engineer.  His email address is Jeremy.Slagley.1@us.af.mil. Dr. Michael E. Miller is a Professor of Systems Engineering at the Air Force Institute of Technology, at Wright Patterson AFB, OH.  He has a B.S. in Industrial and Systems Engineering from the Ohio University, a M.S. in Industrial and Systems Engineering from the Ohio University, and a Ph.D. in Industrial and Systems Engineering, Human Factors Specialty from Virginia Tech. He was previously assigned as a Human Factors and Systems Engineer at Eastman Kodak Company.  His email address is michael.miller.185@us.af.mil. Dr. Gaiven Varshney is a Research Assistant Professor of Nuclear Engineering, and the Co-chair of the Countering Weapons of Mass Destruction Graduate Certificate program at the Air Force Institute of Technology, Wright-Patterson AFB, OH. She has a M.S. in Analytical Chemistry from Aligarh Muslim University (AMU), India, an M.Phil. in Applied Chemistry from Zakir Hussain College of Engineering and Technology, AMU, India, and a Ph.D. in Applied Chemistry from Zakir Hussain College of Engineering and Technology, AMU, India. Her email address is gaiven.varshney@afit.edu and gaiven.varshney.1@us.af.mil  [19] A. 1. C. D. Sanchez, Artist, Negative for COVID. [Art]. Airman Magazine, 2021. [20] S. A. J. Wright, Artist, Negative for COVID. [Art]. Airman Magazine, 2020. [21] T. Burcham, Artist, Negatively Pressurized Conex. [Art]. Airman Magazine, 2021. [22] C. T. Lopez, “Urgent Acquisition Effort Provides Safe COVID-19 Patient Transport in 95 Days,” United States Department of Defense, 7 July 2020. [Online]. Available: https://www.defense.gov/News/News-Stories/Article/Article/2266227/urgent-acquisition-ef-fort-provides-safe-covid-19-patient-transport-in-95-days/. [Accessed 20 April 2022].

Utilizing the System Engineering Trade Study Analysis Method to Analyze Patient Aeromedical Evacuation

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Utilizing the System Engineering Trade Study Analysis Method to Analyze Patient Aeromedical Evacuation

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